"You should be conscious of the risks involved … and fully research the specific project if you are thinking about buying digital tokens," the warning from the Financial Conduct Authority read.

"You should only invest in an ICO project if you are an experienced investor, confident in the quality of the ICO project itself (e.g. business plan, technology, people involved) and prepared to lose your entire stake," .

So it bitcoin definitely doomed?

Not everyone is convinced the sky is falling in on bitcoin.

ThinkMarkets analyst Naeem Aslam said the cryptocurrency had been on a remarkable run.

"This is not the first time that Jamie Dimon has spoken against the currency — the last time he had a similar go on the currency was in November 2015," he said.

"Most importantly, given that the CEO does not think that shorting this trade would yield a more favourable outcome shows that the cryptocurrency has a lot more room to run."